The present invention relates to a box of plastics material of the type comprising a bottom wall with a rectangular shape and four lateral walls projecting therefrom.
The present invention has been developed with the specific object providing a box adapted to contain fruit. Fruit boxes have standard dimensions of 600xc3x97400 mm and are intended to receive on their bottom wall a cell-like element also having standard dimensions and provided with seats which keep separated from each other the various pieces of fruit. In order to be usable for containing fruit, the boxes must have inner dimensions consistent with those of the standard cell-like elements, which are close to the outer dimensions of the boxes. The standardized cell-like elements are specifically formed for containing fruit with defined shape, dimensions and weight. Such elements are standardized on the basis of wood or cardboard boxes already existing on the market which have defined outer dimensions and inner dimensions which differ from the outer ones only for the thickness of the material (wood or cardboard).
In many countries the great majority of fruit is transported into wood or cardboard boxes which are generally disposed after the first use. Disposable cardboard or wood boxes do not comply with recent anti-pollution provisions which impose the use of boxes which can be utilized several times and can be washed after each use.
Re-usable boxes must be carried from the point of sale to a washing centre and after washing must be carried to the production place where they are filled with a new fruit load. Boxes for this type of use must have overall dimensions as low as possible when they are empty, in order to reduce the cost of transportation which represents a relevant part of the total cost of the operations necessary for rendering re-usable the boxes.
A box which meets the above needs and has dimensions consistent with those of standard cell-like elements is known. This box has four lateral walls hinged to the bottom wall and which can be locked in upright position. After use, the lateral wall can be brought down for reducing dimensions during transportation. This box must have relative stout and resistant walls in order to provide an efficient locking thereof in upright position and this is obtained by using a reticular structure with numerous intersecting stiffening ribs both for the bottom wall and the lateral walls.
A box of this type has several drawbacks, the most relevant of which is the fact that it is subject to breakage after repeated assembly and disassembly operations. Furthermore, it is difficult to wash the reticular structure of the box, which has also relatively high weight and cost.
EP-A-0573729 of the same inventor of the present application, discloses a plastic collapsible box provided with removable uprights which have the purpose of the maintaining the lateral walls in a raised position. This box is simpler and less expensive than a box with reticular structure having a snap engagement locking system between the walls, but has the drawback of requiring relevant manpower for assembling and disassembling operations.
DE7435329U discloses a plastic box having the features contained in the preamble of claim 1, comprising a first pair of support elements arranged along a first lateral wall and a second pair of support elements arranged along respective lateral walls orthogonal to the first wall. Boxes of this type can be superimposed to each other when they are alternatively placed with opposite relative orientation and can be interpenetrated (so as to reduce the overall dimensions) when they are placed with the same relative orientation. However, boxes of the type disclosed in DE7435329 have dimensions which are not consistent with the use of standard cell-like elements for containing fruit. Even if the inner dimensions of these boxes where varied so as to receive such cell-like elements, their outer overall dimensions would exceed the maximum outer dimensions which are accepted for fruit boxes because of the dimensions of the system which permits the boxes to be superimposed or interpenetrated. In addition when a plurality of boxes in accordance with DE7435329 are stacked, there are substantial risks of instability of the stack because there is no lateral interpenetration between the boxes.
In order to solve the above problems, the subject of the present invention is a plastics box having the features forming the subject of the main claim.
The present invention provides a superimposable and interpenetrable box having outer dimensions substantially identical to the ones of standard wood or cardboard fruit boxes and with an inner room which can receive the standard cell-like elements. Such cell-like elements are formed so as to avoid that the fruit interferes with the corners of the box where uprights with triangular cross-section are normally located. The invention provides a system which permits the boxes to be superimposed or interpenetrated, which utilizes only the room which in the wood or cardboard boxes is occupied by the triangular uprights.